The present invention relates generally to agricultural implements and more particularly relates to implements capable of being folded rearwardly for storage and transport purposes.
Modern drawn and integral implements are becoming wider and heavier as efforts continue toward increasing farmer productivity and profitability. As implements increase in size, transport and storage present a more significant problem for the farmer. Various means have been devised to reduce the size of implements for transport including rearwardly, forwardly and upwardly folding frame means.
When implement frames are folded rearwardly, it is necessary to prevent the tools mounted at the ends of the adjacent sections from interfering with one another. Consequently some existing rearfold implement frames utilize means to elevate the tool supporting toolbars on all sections prior to folding, while others rearwardly offset the wing sections from the center section by an amount substantially equal to the tool width. For an example of this latter approach, see copending application of assignee Ser. No. 665,067, filed Mar. 8, 1976, and issued Nov. 1, 1977, as U.S. Pat. No. 4,056,149.
A significant disadvantage inherent in those implements which elevate the working tools for transport is that the hinges and frames must be structurally strengthened to withstand the stresses and loadings encountered as the wings are carried in their elevated position. This requirement results in oftentimes burdensome manufacturing and maintenance expenses. Further, seed, fertilizer and other materials carried in hoppers on such implements either have to be emptied prior to transport or can be lost as the hoppers are rotated onto their sides. Further, upwardly folding wing sections are limited as to maximum width since the folded outer sections extend upwardly and will prevent passage beneath rural power lines, trees and other low-hanging obstacles if too high.
In those implements wherein the wing sections are offset from the center section, the tools on adjacent sections operate on fore-and-aft offset transverse lines, thereby resulting in inconsistent tool depth penetration whenever undulating ground contours are encountered. These implements further separate the wing sections from the tractor resulting in more difficult maneuvering and steering during operation.
Forwardly folding implements which fold alongside the tractor naturally have the tools projecting transversely outwardly and present transport hazards and width problems. Further, the projecting tools are exposed to section damage during transport.